Tire

Abstract

In a tire according to the present invention, a decorative portion in which a plurality of minute projections are disposed is formed on a sidewall portion. The decorative portion has a bottom face in which a height of the sidewall portion from a base face gradually increases or gradually decreases. The minute projections are formed at least on the bottom face. Heights of the minute projections are lower than a greatest height of the bottom face. The heights of the plurality of minute projections are the same. The height of a greatest height portion of the minute projections is lower than an outer surface height of the sidewall portion.

Description

Tire

[0001] The present invention relates to a tire.

[0002] Conventionally, it has been proposed to form fine protrusions on the decorative part of the sidewall part of a tire to form a pattern area having contrast (see, for example, Patent Document 1). According to this configuration, it is said that contrast can be exhibited over the entire pattern area.

[0003] Japanese Unexamined Patent Application Publication No. 2019-104396

[0004] An object of the present invention is to widen the range of expression of the visual effect of the decorative part of the sidewall part of a tire.

[0005] The gist configuration of the present invention is as follows. (1) A tire having a decorative part in which a plurality of minute protrusions are arranged on a sidewall part, wherein the decorative part has a bottom surface whose height from the base surface of the sidewall part gradually increases or decreases, the minute protrusions are formed at least on the bottom surface, the height of the minute protrusions is lower than the maximum height of the bottom surface, the plurality of minute protrusions have the same height, and the height of the maximum height part of the minute protrusions is lower than the outer surface height of the sidewall part.

[0006] According to the present invention, the range of expression of the visual effect of the decorative part of the sidewall part of a tire can be widened.

[0007] It is a side view of an example of a tire according to an embodiment of the present invention. It is a partial plan view showing an example of a decorative part. It is a partial cross-sectional view showing an example of a decorative part. It is a plan view showing a part where minute protrusions are formed. It is a diagram for explaining the dimensions of the minute protrusions.

[0008] Embodiments of the present invention will be described in detail below with reference to the drawings. Note that the internal structure of the tire can be the same as that of conventional tires, so a detailed explanation will be omitted. For example, a tire may comprise a pair of bead portions, a pair of sidewall portions connected to the pair of bead portions, and a tread portion connected between the pair of sidewall portions. Furthermore, a tire may comprise a carcass that spans the pair of bead portions in a toroidal manner. Additionally, a tire may comprise a belt positioned radially outward on the crown portion of the carcass.

[0009] Figure 1 is a side view of an example of a tire according to one embodiment of the present invention. As shown in Figure 1, this tire 1 has a decorative section on the sidewall portion with letters, patterns, trademarks, etc. This tire 1 has a decorative section 2 having a plurality of recesses or protrusions (two in the illustrated example). In the illustrated example, the decorative section located between the two plurality of recesses or protrusions of the decorative section 2 is exemplified by the letters "ABC", "DEF", "GHI", "JKLMN", the trademark "X", and the tire size, but in reality, it can display a distinctive trademark (product name, series name, company logo, etc.) or the actual tire size.

[0010] Figure 2 is a partial plan view showing an example of a decorative part. Figure 3 is a partial cross-sectional view showing an example of a decorative part. As shown in Figures 2 and 3, the decorative part 2 has a plurality of recesses 3 (or protrusions). The recesses 3 are recessed portions relative to the outer surface 4 of the sidewall portion of the tire 1. These recesses 3 define the protrusions that project from the base surface 5 of the sidewall portion. Therefore, the decorative part 2 has a plurality of recesses 3 and a plurality of protrusions at the same time.

[0011] As shown in Figures 2 and 3, the depth (or height) of the multiple recesses 3 (or protrusions) within the decorative part 2 changes continuously in the tire radial direction and tire circumferential direction. In other words, the portion of the decorative part 2 formed by the multiple recesses 3 (or protrusions) does not have any portion with a constant depth (or height).

[0012] As shown in Figure 3, the decorative part 2 has a bottom surface (the surface of the convex part partitioned by the recess 3) whose height from the base surface 5 of the sidewall gradually increases or decreases. In the illustrated example, the height of the bottom surface from the base surface 5 alternates between gradually increasing and gradually decreasing from one side to the other in the left-right direction shown in the illustration.

[0013] As shown in Figure 3, this tire 1 has a decorative section 2 formed on the sidewall portion, which consists of multiple micro-protrusions 6, and the micro-protrusions 6 are formed on at least the bottom surface. In the illustrated example, the micro-protrusions 6 are arranged only on a part of the bottom surface (the surface of a part of the protrusions).

[0014] Figure 5 is a diagram illustrating the dimensions of the micro-protrusions. Note that, for simplicity, Figure 5 shows multiple micro-protrusions 6 protruding from a base surface of the same height; however, in reality, the height of the bottom surface gradually increases or decreases from the base surface. As shown in Figures 3 and 5, the height h1 of the micro-protrusions 6 is lower than the maximum height h of the bottom surface. Furthermore, multiple micro-protrusions 6 have the same height h1. Also, the height (h + h1) of the maximum height portion of the micro-protrusions 6 (from the base surface 5) is lower than the height H of the outer surface 4 of the sidewall portion (from the base surface 5). The effects and advantages of the tire of this embodiment will now be explained.

[0015] The tire 1 of this embodiment has a decorative section 2 formed on the sidewall portion, which consists of multiple minute protrusions 6, and the minute protrusions 6 are formed at least on the bottom surface. The height h1 of the minute protrusions 6 is lower than the maximum height h of the bottom surface. Also, the height h1 is the same for all of the minute protrusions 6. Furthermore, the height (h + h1) of the maximum height portion of the minute protrusions 6 (from the base surface 5) is lower than the height H of the outer surface 4 of the sidewall portion (from the base surface 5). Light incident on the decorative section 2 is attenuated by repeatedly reflecting off the sides of adjacent minute protrusions 6 and is reflected to the outside of the tire 1, so the minute protrusions 6 produce a contrast effect in which the portion on which the minute protrusions 6 are formed appears dark. According to the configuration of this embodiment, since the minute protrusions 6 are made to be low in height as described above, this contrast effect can be moderately reduced. As a result, the impression of the decorative section 2 on which the minute protrusions 6 are formed can be moderately weakened, and attention can be drawn to other decorative sections that you want to stand out the most. As described above, the tire 1 of this embodiment provides a different visual effect from conventional tire 1, thereby broadening the range of visual effect expression for the decorative part 2 on the sidewall of the tire 1.

[0016] The height h1 of the minute protrusion 6 is preferably 50% or less of the maximum height h of the base. This is because it allows for a moderate reduction in the contrast effect, drawing more attention to other decorative parts that you want to stand out the most.

[0017] It is preferable that at least a portion of the base surface be curved, as this provides a contrast effect. It is preferable that 90% or more of the total surface area of ​​the base surface be formed as a curved surface, and it is more preferable that 100% of the total surface area be formed as a curved surface. The portion other than the curved surface can be formed as a flat surface. The curved surface can be formed as consisting of one or more circular arcs in cross-sectional view. In the case of a single circular arc, or when multiple circular arcs are approximated into a single circular arc by the least squares method, the radius of curvature of the curved surface is not particularly limited, but can be, for example, 10 to 250 mm.

[0018] In the example shown in Figure 2, the recess 3 is weight-shaped in plan view (a shape in which the width of the central part is smaller than the width of both ends in the longitudinal direction, resulting in a recess), but it is not limited to this case and can be various planar shapes. Examples include circular, elliptical, polygonal, star-shaped, leaf-shaped, etc., in plan view. Furthermore, the weight-shaped example shown is a complementary shape in which both ends in the longitudinal direction of one recess 3 fit into the recess in the longitudinal center of an adjacent recess 3 (rotated by approximately 90°) in the longitudinal direction. Thus, it is also preferable for the planar shape of the recess 3 to be a complementary shape. The recesses 3 are arranged in multiple rows. Within the same row, in this example, adjacent weight shapes are arranged alternately, rotated by approximately 90°, so that they fit complementaryly. In adjacent rows to one row, the adjacent weight shapes are offset by one pitch (the width of one weight) from the row so that they fit complementaryly between rows.

[0019] The maximum diameter of the recess 3 in a plan view (the maximum distance between two points on the contour line of the recess 3) is not particularly limited, but can be, for example, 3.0 to 30.0 mm.

[0020] As shown in Figure 3, it is preferable that the maximum height h of the protrusion partitioned by the recess 3 from the base surface 5 is smaller than the height H of the sidewall portion from the base surface 5 to the outer surface 4. The ratio h / H can be, for example, 0.25 to 0.90, although it is not particularly limited. The minimum depth d (= H - h) of the recess 3 can be, for example, 0.01 to 0.40 mm, although it is not particularly limited.

[0021] The number density of recesses 3 in the decorative part 2 is not particularly limited, but for example, 0.5 to 8 recesses / cm². ２ It can be done this way.

[0022] Figure 4 is a plan view showing the portion where the micro-protrusions are formed. As shown in Figure 4, the micro-protrusions 6 are preferably asterisk-shaped in plan view. That is, the micro-protrusions 6 are preferably shaped having multiple extending portions radiating from the center in plan view. The number, width, and length of the extending portions are not particularly limited and can be set as appropriate. The spacing between the centers of the multiple asterisk shapes is also not particularly limited and can be set as appropriate. Furthermore, as shown in the figure, some of the extending portions between the multiple asterisk shapes may be connected to each other. The planar shape of the micro-protrusions 6 can be various, and the above asterisk shape is an example.

[0023] The height h1 of the microprojection 6 is not particularly limited, but can be, for example, 0.05 to 0.5 mm. Also, the apex angle θ of the microprojection 6 (see Figure 5) is not particularly limited, but can be, for example, 20 to 90°.

[0024] The number density of the minute projections 6 is not particularly limited, but for example, 10 to 40 projections / cm² ２ This can be done. Furthermore, in the case of an asterisk shape in plan view, the density of intersection points of the asterisk shape is not particularly limited, but for example, 10 to 40 points / cm². ２ It can be done this way.

[0025] 1: Tire, 2: Decorative part, 3: Recess, 4: Outer surface, 5: Base surface, 6: Micro-protrusion, 100, 200: Communication device

Claims

1. A tire having a decorative portion formed on the sidewall portion, wherein the decorative portion has a bottom surface whose height from the base surface of the sidewall portion gradually increases or decreases, the micro-protrusions are formed on at least the bottom surface, the height of the micro-protrusions is lower than the maximum height of the bottom surface, the multiple micro-protrusions are of the same height, and the height of the highest portion of the micro-protrusions is lower than the height of the outer surface of the sidewall portion.

2. The tire according to claim 1, wherein the height of the minute protrusions is 50% or less of the maximum height of the bottom surface.

3. The tire according to claim 1 or 2, wherein at least a portion of the bottom surface is curved.

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